Gripping mechanism



Oct..16, 1934. A. HAM 1,976,848

GRIPPING MECHANISM Filed June 14, .1933 2 Sheets-Sheet l Oct. 16, 1934. HAM 1,976,848

I GRIPPING MECHANISM Filed June 14, 1933 2 Sheets-Sheet 2 Patented Got. is. 1934.

.TATES .siE

2 Claims.

n metal plates, and it has for its object to provide an efiicient and safe device of this class which will be of simple and inexpensive construction.

In the accompanying drawings:

Figure 1 is a front elevation of a plate-gripping mechanism constructed in accordance with my invention.

Figure 2 is a side elevation of the mechanism shown in Figure 1.

Figure 3 is a section on line 3-3 of Figure 1.

The embodiment of my invention herein illustrated comprises a body member 1 which may be a steel casting. Adjacent to its top this body member 1 is provided with an ear 2 formed with an aperture 3 to be connected with the cable or the like a of a derrick or crane. The lower part of body member 1 is formed with two opposed de- 40': upon a pintle 1 1.

pending jaws 5 and 6 which are spaced apart as shown in Figure l to provide between them a vertical slot '7 adapted to receive the marginal portion of the metal plate that is to be lifted.

The inner side of the jaw 6 bordering slot 7 is made with a vertical fiat surface 8 which is preferably knurled or otherwise roughened. This surface 8 may be the exposed face of a hardened steel plate 9 fastened to the jaw 6 by means of screws 1 10 and 11 so that a new plate 9 may be substituted when desired.

The inner side of the jaw 5 is made with an inclined fiat surface 12 disposed opposite the plate 9, said inclined surface 12 being steeply inclined '1 from its upper end downwardly toward the opposite jaw 6.

cooperatively associated with the inclined surface 12 is a cylindrical exteriorly knurled or roughened clutch roll 13 that is rotatably mounted This pintle is supported adjacent to its opposite ends by a pair of slide bars 15. The pintle 14 is held in position by means of cotter pins 16 so that when desired a worn roll 13 may be replaced by a new one.

Each slide bar is slidably mounted in a way or groove 17 parallel with the inclined surface 12 and is loosely held therein by screws 18 occupying threaded holes formed in body member 1 and extending through longitudinal slots 19 formed in the slide bar.

Fulcrumed at 29 on body member 1 is a lever 21 which is bifurcated so as to provide the same with two arms 21a, 21a, between which the body member 1 is disposed and each of which is pivotally connected at 20 with said body member.

The lever 21 is a bell crank provided with two relatively short arms 21b, each of which is formednear its free end with a radial slot 210 to accommodatea stud screw 22 by which said arm is connected with the adjacent slide bar 15, said stud screw 18 being carried by the latter.

The longer arm of the bell crank lever 21 is pro- Vided with an eye 23 connected by a spring 24 with an eye 25 attached to the lug or car 2. The spring 24 acts through bell crank lever 21 to yieldingly hold the slide bars 15 and clutch roll 13 at the limit of their downward movement with the upper ends of the slots 19 against the stud screws 18.

Upon the outer side of the jaw 5 is provided a handle 26 by means of which the device may be manually guided or controlled while it is being applied to, or removed from a plate. When the device is to be applied to a steel plate the gripping mechanism is lowered while guided by means of the handle 26 so that the top marginal portion of the plate enters the slot '7. As the body member 1 continues to descend, the clutch roll 13 and slide bars 15 are shoved upwardly relatively to body 1 against the force of spring 24 until the top edge of the plate passes the clutch roll. As will be clear the body member 1 may thereafter continue to descend until the top edge of the steel plate engages the inner end wall of slot 7. 'It will be clear that when body member 1 is thereafter carried upwardly by means of cable 4 to lift the steel plate, the engagement of the latter with the clutch roll 13 will tend to roll the latter downwardly on the inclined surface 12 with the result that the steel plate is clamped between the two jaws with great force and cannot slip out of the device. It will also be clear that the spring 24 assures effective frictional engagement between the clutch roll 13 and the steel plate at the very start of the upward movement of body member 1 and holds said clutch roll in clutching engagement with the plate during all the time that the latter is being transported by means of cable 4.. When the plate is to be released, it is lowered on to the ground or other support and then the lever 21 is manually operated to shift the slide bars 15 and clutch roll 13 upwardly after which the body member 1 is removed from the plate either by means of the handle 26 or by upward movement of cable 1.

It is a feature of advantage to the above described device that the axis of the clutch roll 13 is at all times maintained parallel with the two obliquely disposed surfaces 8 and 12 by means of the slide bars 15 and lever 21. It is also a feature of advantage that the spring 24 yieldingly but strongly assists in holding the clutch roll 13 in clutching engagement with the steel plate while the latter is held by the gripping mechanism with the result that the maximum degree of safety is afforded.

In order to ensure contact at all times between the clutch roll and the inclined surface, the bore of the clutch roll may be made slightly larger than the outside diameter of the pintle 14. This prevents injurious strains and stresses being imposed upon the side bars while the device is in clutching engagement with a plate.

What I claim is:

l. A gripping device of the character described comprising a body member provided adjacent to its top with means for attachment to a cable or the like and having its lower portion formed with a pair of depending opposed spaced apart jaws adapted to receive between them the marginal portion of a plate, one of said jaws having its inner side provided with a vertically disposed plate-engaging surface and the other jaw having its inner side provided with an inclined surface disposed opposite the vertical surface of the other jaw and sloping acutely downwardly toward the latter; a clutch roll between said two surfaces; a carrier for said clutch roll slidably mounted upon said body member and movable thereon upon a path that is parallel with said inclined surface so as to maintain said clutch roll in contact with the latter; a bell crank lever pivotally mounted upon said body member and having a relatively short arm connected with said carrier and a relatively long arm, said lever being manually operable to shift said carrier and roll relatively to said inclined surface, and a spring connected with said relatively long arm so as to yieldingly urge said carrier and roll toward said vertical surface.

2. A gripping device of the character described constructed in accordance with claim 1 wherein said carrier comprises a pair of slide bars mounted upon opposite sides of said body member by and between which said clutch roll is rotatably supported, and wherein said lever is bifurcated and embraces said body member, each arm of said lever being connected with one of said slide bars.

ASA HAM. 

